Can you explain why the 50% rule is a good rule? Why isn't it 10Mbit/sec?

Hmm, yes, especially since Ed's transfer, if it really was 30 GB, apparently ran in about a third the estimated time.

Ooops... wait a minute.

30 GBytes * 8-bits/byte = 320 Gbits @ 5Mbits/sec = 64000 secs = 1066 mins = 17.8 hours.

Umm, wouldn't that be 240 Gbits, and 13.3 hours at 5Mbits/sec? That would make Ed's reported 6:38 transfter time exactly 10Mbits/sec.

tanstaafl.